Fix typo

src/main.c

@@ -174,7 +174,7 @@ int main(int argc, char **argv) {
     printf("[minisolver] batch input file = %s\n", batch_input);
     printf("[minisolver] batch output file = %s\n", batch_output);
 
-    printf("[minisolver] runnin test batch ... ");
+    printf("[minisolver] running test batch ... ");
     ierr = run_batch(); CHKERRQ(ierr);
     printf("done\n");